Could eggshell nanoparticles be the next step up for bioplastics?
A group of scientists at Tuskegee University in Alabama have been experimenting with how to improve the properties of bioplastics, and believe that nano-sized eggshell particles may be the secret weapon to enhance biodegradable plastics.
Biodegradable plastics have been heralded for their enhanced eco-friendly credentials, but have sometimes failed to reach the mark in both their aesthetics and functionality, issues that the scientists hope to address this with this research.
Using a material that is otherwise discarded
It also hits on a byproduct that is often discarded and unused, despite the fact that eggshell material is both natural and extremely strong.
The research group is about to present its findings at the 251st National Meeting & Exposition of the American Chemical Society, which is being held this week and features more than 12,500 presentations on a spectrum of topics.
"We're breaking eggshells down into their most minute components and then infusing them into a special blend of bioplastics that we have developed," says Vijaya K. Rangari, Ph.D, who is leading the project.
"These nano-sized eggshell particles add strength to the material and make them far more flexible than other bioplastics on the market. We believe that these traits -- along with its biodegradability in the soil -- could make this eggshell bioplastic a very attractive alternative packaging material."
Adding strength and flexibility
The major shortfall with regular plastics is that they are almost entirely made of crude oil or other non-renewable fossil fuels, which can take centuries to degrade once they are discarded.
The popular alternative is bioplastics, but because such plastics can lack strength and flexibility, they have been challenging to use in packaging applications, which in the cosmetics and personal care arena means they are required to hold, encase and wrap products.
Rangari and his team first focused on plastic polymers to find a solution, and eventually settled on a mixture of 70% polybutyrate adipate terephthalate (PBAT), a petroleum polymer, and 30% polylactic acid (PLA), a polymer derived from cornstarch. PBAT, which can biodegrade in three months.
To this formula, the scientists added eggshells that had been broken down to less than 350,000 times small than the diameter of a human hair, which were infused into the 70/30 PBAT and PLA mixture.
The team says that the resulting plastic is lightweight and highly flexible, giving it applications for all types of retail consumer goods.
